ANÁLISE DA TEMPERATURA SUPERFICIAL DE TELHAS CERÂMICAS E DE FIBROCIMENTO COM DIFERENTES ABSORTÂNCIAS

Abstract

The knowledge of the effect of materials chosen for the building envelope is important for effective design decisions for each type of climate. Contributing to this discussion, this paper aims to analyze the surface temperature of natural and resin-coated ceramic roof tiles, and fiber cement roofing sheets exposed to the sun, relating it to their solar absorptance. In this context, spectral reflectance was measured for samples of 27 selected tiles using a spectrophotometer with an integrating sphere, and the solar absorptance of the roof tiles were calculated. The surface temperatures of the roof tiles were measured on three different days due to the number of samples analyzed, exposing them to the sun for 3 hours and measuring the temperature every 6 minutes. The results show that an increase of up to 20% in the solar absorptance of the roof tiles, for the three types analyzed, corresponds to an increase of approximately 5°C in their surface temperature. It was also concluded that the surface finish of the roof tiles, such as their porosity and homogeneity of finish, are important factors for the surface temperature variations of roof tiles with similar solar absorptance values.